Adequate wound care and use of bed nets as protective factors against Buruli Ulcer: results from a case control study in Cameroon.

BACKGROUND: Buruli ulcer is an infectious disease involving the skin, caused by Mycobacterium ulcerans. Its exact transmission mechanism remains unknown. Several arguments indicate a possible role for insects in its transmission. A previous case-control study in the Nyong valley region in central Cameroon showed an unexpected association between bed net use and protection against Buruli ulcer. We investigated whether this association persisted in a newly discovered endemic Buruli ulcer focus in Bankim, northwestern Cameroon. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a case-control study on 77 Buruli ulcer cases and 153 age-, gender- and village-matched controls. Participants were interviewed about their activities and habits. Multivariate conditional logistic regression analysis identified systematic use of a bed net (Odds-Ratio (OR) = 0.4, 95% Confidence Interval [95%CI] = [0.2-0.9], p-value (p) = 0.04), cleansing wounds with soap (OR [95%CI] = 0.1 [0.03-0.3], p<0.0001) and growing cassava (OR [95%CI] = 0.3 [0.2-0.7], p = 0.005) as independent protective factors. Independent risk factors were bathing in the Mbam River (OR [95%CI] = 6.9 [1.4-35], p = 0.02) and reporting scratch lesions after insect bites (OR [95%CI] = 2.7 [1.4-5.4], p = 0.004). The proportion of cases that could be prevented by systematic bed net use was 32%, and by adequate wound care was 34%. CONCLUSIONS/SIGNIFICANCE: Our study confirms that two previously identified factors, adequate wound care and bed net use, significantly decreased the risk of Buruli ulcer. These associations withstand generalization to different geographic, climatic and epidemiologic settings. Involvement of insects in the household environment, and the relationship between wound hygiene and M. ulcerans infection should now be investigated

Clinical evolution of TB patient discovered in BU-endemic area.

<p>A 27-year-old male presented to an integrated health centre in a BU-endemic area in Cameroon with multiple lesions on the neck and upper chest. After acid-fast bacilli were observed in the wound exudates, the patient was diagnosed with BU and treated according to WHO guidelines. <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001751#pntd-0001751-g001" target="_blank">Figure 1A</a> shows the patient on day 17 of BU treatment. The lesions healed following eight weeks of rifampicin/streptomycin combination therapy. <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001751#pntd-0001751-g001" target="_blank">Figure 1B and C</a> show the patient 86 and 178 days after completion of BU treatment, respectively. Further laboratory analysis on the original wound exudates showed that the patient was suffering from TB as opposed to BU, and the appropriate long-term TB treatment was administered.</p